@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if (mScrollView != null) {
measureChild(
mScrollView,
MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(widthMeasureSpec), MeasureSpec.AT_MOST),
MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(heightMeasureSpec), MeasureSpec.AT_MOST));
mScrollContentHeight = mScrollView.getChildAt(0).getMeasuredHeight();
mScrollViewHeight = mScrollView.getMeasuredHeight();
}
if (mBackground != null) {
int minHeight = 0;
minHeight =
(int) (mScrollViewHeight + mParallaxOffset * (mScrollContentHeight - mScrollViewHeight));
minHeight = Math.max(minHeight, MeasureSpec.getSize(heightMeasureSpec));
measureChild(
mBackground,
MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(widthMeasureSpec), MeasureSpec.EXACTLY),
MeasureSpec.makeMeasureSpec(minHeight, MeasureSpec.EXACTLY));
mBackgroundRight = getLeft() + mBackground.getMeasuredWidth();
mBackgroundBottom = getTop() + mBackground.getMeasuredHeight();
mScrollDiff =
(float) (mBackground.getMeasuredHeight() - mScrollViewHeight)
/ (float) (mScrollContentHeight - mScrollViewHeight);
}
}
